Superimpose matrices of different sizes

Hello,

I have matrix A 2x5 of NaN

A=...
[NaN NaN NaN NaN NaN;
NaN NaN NaN NaN NaN]

and another B matrix 2x3:

B=...
[NaN 6 2;
NaN 1 0]

If the elements of B are postive (so not 0 nor NaN) I want to paste those elements into A, call this result matrix C

C=...
[NaN 6 2 NaN NaN;
NaN 1 NaN NaN NaN]

Thanks

Answer 1

[Azzi Abdelmalek]

EDIT

C=A
B(B==0)=nan
C(1:size(B,1),1:size(B,2))=B

%or

A=nan(2,5)
B=[NaN 6 2;NaN 1 0]
x=B>0;
[ii,jj]=find(x)
idx=sub2ind(size(A),ii,jj)
C=A;
C(idx)=B(x)

[Thorsten]

This does not work for the entry in B that is 0, which should not be copied.

[Dave]

Thanks Azzi and Thorsten, not allowed to accept both answers here. yeah, doesn't consider the 0 case (before the EDIT changes), but can do C(C==0)=NaN afterwards.

Answer 2

[Thorsten]

This works only if A and B have the same number of rows:

 ind = find(B>0);
 C = A;
 C(ind) = B(ind);